section.section
  header.section__header
    h2.section__title Methods
  div.section__content
    p outline.js 的提供的方法如下：
  include ./attr
  include ./isExpanded
  include ./getChapters
  include ./count
  include ./addButton
  include ./removeButton
  include ./toTop
  include ./toBottom
  include ./scrollTo
  include ./expand
  include ./collapses
  include ./toggle
  include ./print
  include ./enterReading
  include ./exitReading
  include ./switchReading
  include ./destroy
  include ./refresh
  include ./reload
  include ./$emit
  include ./$on
  include ./$off
